/Engine/Plugins/Animation/ControlRig/Source/ControlRig/Public/Rigs/RigHierarchy.h
Returns the indices of an array of keys
The indices of the elements or INDEX_NONE
[TArray](API\Runtime\Core\Containers\TArray)< int32 > GetIndices ( const [TArray](API\Runtime\Core\Containers\TArray)< [FRigElementKey](API\Plugins\ControlRig\Rigs\FRigElementKey) > & InKeys ) const